Methods and systems for material fixation

ABSTRACT

A soft tissue fixation system, most typically applicable to orthopedic joint repairs, such as anterior cruciate ligament (ACL) knee repair procedures, comprises an implant which is placeable in a tunnel disposed in a portion of bone, wherein the tunnel is defined by walls comprised of bone. A first member is deployable outwardly to engage the tunnel walls for anchoring the implant in place in the tunnel, and a second member is deployable outwardly to engage tissue material to be fixed within the tunnel. The second member also functions to move the tissue material outwardly into contact with the tunnel walls to promote tendon-bone fixation. Extra graft length is eliminated by compression of the tendon against the bone at the aperture of the femoral tunnel, which more closely replicates the native ACL and increases graft stiffness. The inventive device provides high fixation of tendon to bone and active tendon-bone compression. Graft strength has been found to be greater than 1,000 N (Newtons), which is desirable for ACL reconstruction systems.

This application is a continuation application under 35 U.S.C. 120 ofcommonly assigned U.S. patent application Ser. No. 11/923,526, entitledMethods and Systems for Material Fixation, filed Oct. 24, 2007, nowallowed, which in turn claims the benefit under 35 U.S.C. 119(e) of thefiling date of Provisional U.S. Application Ser. No. 60/854,178,entitled Methods and Systems for Material Fixation, filed on Oct. 24,2006. Each of the above referenced applications are which application isexpressly incorporated herein by reference, in their entirety.

This application is also related to co-pending U.S. application Ser. No.11/281,566 entitled Devices, Systems, and Methods for Material Fixation,filed on Nov. 18, 2005 and published as U.S. Patent ApplicationPublication No. US 2006/0155287 on Jul. 13, 2006, and to co-pending U.S.application Ser. No. 11/725,981, entitled Devices, Systems, and Methodsfor Material Fixation, filed on Mar. 20, 2007. Both of these priorpending applications are commonly owned and herein expresslyincorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to devices, systems and methodsfor material fixation. More specifically, the present invention relatesto a technique that can be used to firmly hold a soft tissue or graftagainst bone tissue within a bone tunnel.

One of the most common needs in orthopedic surgery is the fixation oftendon to bone. The fixation of diseased tendons into a modifiedposition is called tenodesis and is commonly required in patients withinjury to the long head of the biceps tendon in the shoulder. Inaddition, tendons which are torn from their insertion site into bonealso frequently require repair. This includes distal biceps tendontears, rotator cuff tears, and torn flexor tendons in the hand. Tendonsare also frequently used in the reconstruction of unstable joints.Common examples include anterior cruciate ligament and collateralligament reconstructions of the knee, medial and lateral elbowcollateral ligament reconstructions, ankle collateral ligamentreconstruction, finger and hand collateral ligament reconstructions andthe like.

Traditional techniques that are used to fix tendon to bone suffer from anumber of limitations as a result of the methodology used, including theuse of a “keyhole” tenodesis, pull-out sutures, bone tunnels, andinterference screw fixation. The “keyhole” tenodesis requires thecreation of a bone tunnel in the shape of a keyhole, which allows aknotted tendon to be inserted into the upper portion, and subsequentlywedged into the lower narrower portion of the tunnel where inherenttraction on the tendon holds it in place. This technique is challengingas it is often difficult to sculpt the keyhole site and insert thetendon into the tunnel. In addition, if the tendon knot unravels in thepostoperative period, the tendon will slide out of the keyhole, losingfixation.

Another traditional form of tendon fixation is the use of the “pull-outstitch.” With this technique, sutures attached to the tendon end arepassed through bone tunnels and tied over a post or button on theopposite side of the joint. This technique has lost favor in recentyears due to a host of associated complications, which include woundproblems, weak fixation strength, and potential injury to adjacentstructures.

The most common method of fixation of tendon to bone is the use of bonetunnels with either suture fixation, or interference screw fixation. Thecreation of bone tunnels is relatively complicated, often requiring anextensive exposure to identify the margins of the tunnels. Drill holesplaced at right angles are connected using small curettes. This tediousprocess is time-consuming and fraught with complications, which includepoor tunnel placement and fracture of the overlying bone bridge. Graftisometry, which is easy to determine with single point fixation, isdifficult to achieve because the tendon exits the bone from two points.After creation of tunnels, sutures must be passed through the tunnels tofacilitate the passage of the tendon graft. Tunnels should be smallenough to allow good tendon-bone contact, yet large enough to allow forgraft passage without compromising the tendon. This portion of theprocedure is often time-consuming and frustrating to a surgeon. Finally,the procedure can be compromised if the bone bridge above the tunnelbreaks, resulting in loss of fixation. The technique restricts fixationto the strength of the sutures, and does not provide any direct tendonto bone compression.

More recent advances in the field of tendon fixation involve the use ofan internally deployed toggle button, for example, the EndoButton®, andthe use of interference screws to provide fixation. The EndoButton, bySmith & Nephew, allows the fixation of tendon into a bone tunnel bycreating an internally deployed post against a bony wall. While thistechnique eliminates the need for secondary incisions to place the post,the fixation strength is limited to suture strength alone. Thistechnique does not provide direct tendon to bone compression; as suchthis technique may slow healing and lead to graft tunnel widening due tothe “bungee effect” and “windshield wiper effect”. As a result, thistechnique has limited clinical applications and is used primarily forsalvage when bone tunnels break or backup fixation is important.

The use of the interference screw is the most notable advance in thefixation of tendon to bone. The screw is inserted adjacent to a tendonin a bone tunnel, providing axial compression between the screw threadsand the bony wall. Advantages include acceptable pull-out strength andrelative ease of use. Aperture fixation, the ability to fix the tendonto bone at its entrance site, is a valuable adjunct to this technique asit minimizes graft motion and subsequent tunnel widening. Somedisadvantages related to soft tissue interference screws are that theycan be difficult to use, and can also cut or compromise the tendonduring implantation.

The newest generation interference screw allows the ability to providetendon to bone fixation with limited exposure. For example, theBio-Tenodesis Screw™ (Arthrex, Inc.) allows the tensioning and insertionof tendon into bone, followed by insertion of an adjacent soft tissueinterference screw. While this screw system provides advantages in theinsertion of tendon into bone in cases when a pull through stitch is notavailable, it is still limited by the potential for tendon rotation ordisruption as the screw compresses the tendon. The surgical technique isalso complicated, typically requiring two or more hands for insertion,making it difficult to use the system without assistance duringarthroscopic or open procedures. Finally, the use of the screw requirespreparation of the tendon end, which can be difficult, time consuming,and can also require conversion of an arthroscopic procedure to open.

Referring particularly to the field of repairing an anterior cruciateligament (ACL) injury, current repair techniques utilizing soft tissuefor the replacement graft are either difficult to perform or they resultin less than favorable outcomes due to their relatively lowtendon-to-bone fixation. Existing ACL reconstruction techniques thathave acceptable outcomes (high tendon-to-bone fixation strength) requireextra operating room time and surgeon effort due to the requirements ofmultiple drill holes, external guides and fixtures for the drill holes,and multiple assistants. Another difficulty with current techniques isthat they do not well replicate the native ACL in its anatomy orphysiology.

Two important factors in replicating the native ACL are aperturecompression (compressing the tendon against the bone at the opening ofthe drill hole into the joint) and tendon length. Compression of thetendons at the aperture of the femoral tunnel will improve the healingprocess by increasing the intimate contact between the tendon and thebone. Studies show that the lack of intimate contact between the tendonand bone can result in less well organized fibrous tissue, resulting inlower pull-out strengths. The stiffness of the repair is also importantto replicate the native ACL. Graft stiffness is decreased by the lengthof tendon between the fixation points.

Currently, two different sources are utilized for the tissue thatreplaces the injured native ACL. When the new tissue comes from thepatient's own body, the new graft is referred to as an autograft, andwhen cadaveric tissue is used, the new graft is referred to as anallograft. The most common autograft ACL reconstruction performedcurrently is the bone-patellar tendon-bone (BTB) graft. The BTB graftfixed with an interference screw is used more often because it moreaccurately replicates the native ACL, due to its aperture compression atthe femoral tunnel aperture. However, BTB reconstructions result in anincreased rate of anterior knee pain post-surgically for periods of upto 3 years after the reconstruction. Additionally, the harvest procedurefor the BTB autograft is invasive and can be difficult to perform.Alternatively, the hamstring tendon autograft ACL reconstructiontechnique does not result in any significant post-surgical pain, and theharvest procedure is minimally invasive compared to the BTB graftharvest. The reason that the hamstring tendon autograft procedure is notused more frequently in ACL reconstructions is that the fixation of thehamstring tendons to the femur and tibia are not as strong as thefixation of the BTB autografts.

Many prior art systems have addressed some of the problems associatedwith ACL reconstruction using hamstring tendons, but there is not onesystem that addresses them all. For example, the EndoButton system(Smith & Nephew) is easy to use and does not need additional drillholes. However, it does require additional accessories and additionalpeople to perform the procedure and does not replicate the native ACLdue to a lack of tendon-to-bone compression at the aperture, as well asadditional length of tendon between fixation points. The EndoButtonsystem is an example of a cortical hamstring fixation device that yieldsa longer graft construct, resulting in a graft that is less stiff thanthe native ACL. Peer reviewed journal data show that existing softtissue fixation systems with long graft lengths between fixation pointshave as much as a 56% reduction in graft stiffness when compared to thenative ACL.

The RigidFix® product by Mitek is a cross pin device that requiresmultiple drill holes, additional instruments, and assistance from otherpeople in the operating room to complete the repair. Also, there is onlypassive compression of tendon to bone, not direct, active compression.

The Stratis® ST product by Scandius attempts to more accuratelyreplicate the native ACL by adding material to take up space in thefemoral tunnel resulting in more intimate contact between the tendon andthe bone. However, to insert the device into the femoral tunnel, thecross-sectional area must be less than the cross-sectional area of thehole. Thus, there is no real compression of tendon to bone. The StratisST product also requires additional drill holes, accessories, and peopleto properly perform the procedure.

The EZLOC™ product by Arthrotek provides high strength and attempts tomore accurately replicate the native ACL in the same fashion as theStratis ST product, by taking up the space in the femoral tunnel. Thisdoes create more intimate contact between the tendon and bone, but doesnot offer real compression at the aperture.

Interference screws such as the RCI™ Screw, available from Smith &Nephew, are easy to use and provide compression of tendon to bone at thefemoral tunnel aperture. However, the pull-out strength and stiffness ofthe repair are significantly lower than the preceding systems.

Thus, although there are many conventional techniques used for thefixation of tendon to bone, each having some advantages, thedisadvantages of each such technique presents a need in the art for asimple and universal technique to fixate tendon to bone such that thedevice is easy to use, the process is simple to follow, and the resultis a firm and secure tendon to bone fixation with minimal negativeeffect on the tendon. Further, such device should be easy tomanufacture, universally applied to different tendon to bone sites, andrequire minimal effort to understand and use in practice.

SUMMARY OF THE INVENTION

The present invention is a device that is easy to use, provides highfixation of tendon-bone and active tendon-bone compression, requires noadditional accessories, uses only one drill hole, and can be implantedby one practitioner. The invention utilizes cancelous bone for fixation,and replicates the native ACL by compressing the tendons against thebone at the aperture of the femoral tunnel, effectively shortening thelength of the graft as compared to cortical hamstring fixation devices.An important advantage of the invention is the improvement of thetendon-bone fixation of hamstring autografts as well as othersoft-tissue ACL reconstruction techniques. Extra graft length iseliminated by compression of the tendon against the bone at the apertureof the femoral tunnel, which more closely replicates the native ACL andincreases graft stiffness. The inventive device provides high fixationof tendon to bone and active tendon-bone compression. Graft strength hasbeen found to be greater than 1,000 N (Newtons), which is desirable forACL reconstruction systems.

More particularly, there is provided in one aspect of the invention amaterial fixation system, which comprises an implant which is placeablein a tunnel disposed in a portion of bone, wherein the tunnel is definedby walls comprised of bone. A first member is deployable outwardly toengage the tunnel walls for anchoring the implant in place in thetunnel, and a second member is deployable outwardly to engage tissuematerial to be fixed within the tunnel. The second member also functionsto move the tissue material outwardly into contact with the tunnelwalls. A third member forming a part of the implant is movable to deploythe first member outwardly. A fourth member is provided actuating thethird member to move in order to deploy the first member.

Preferably, the fourth member comprises a portion which functions todeploy the second member outwardly. The implant comprises a body havinga distal end and a proximal end, and the first member is disposed on thebody. The first member comprises an arm which is pivotally attached tothe body. The third member comprises a wedge which is movable generallyaxially to deploy the arm.

In one presently preferred embodiment, the fourth member comprises adeployment screw having a distal end and a proximal end, wherein thedeployment screw is adapted to extend axially through the body. Thedistal end of the deployment screw has a threaded portion which isengageable with a complementary threaded portion on the wedge, whereinrotation of the deployment screw causes relative movement of thedeployment screw and the wedge. The wedge moves proximally to deploy thearm.

The aforementioned second member comprises a compression pad. In thepreferred embodiment, the fourth member portion comprises a head of thedeployment screw, disposed on the proximal end thereof.

In another aspect of the invention, there is provided an anchor forsecuring soft tissue into a portion of bone, which comprises a bodyportion having a distal end and a proximal end. At least one outwardlydeployable anchoring member is disposed on the body. A wedge member ismovable for deploying the at least one outwardly deployable anchoringmember. The anchor further comprises a generally axially movabledeploying member for moving the wedge member. The deploying memberengages the wedge member to move the wedge member, and is disposedproximally of the wedge member.

Preferably, the aforementioned wedge member is disposed distally of theoutwardly deployable anchoring member, and moves proximally in order todeploy the outwardly deployable anchoring member outwardly. The anchorfurther comprises an outwardly deployable compression member forengaging a portion of soft tissue and pushing the soft tissue outwardlyinto contact with adjacent bone. The outwardly deployable compressionmember is proximal to the outwardly deployable anchoring member. Aportion of the generally axially movable deploying member is adapted todeploy the compression member outwardly. Again, referencing currentlypreferred embodiments, the at least one outwardly deployable anchoringmember comprises an arm pivotally attached to the body, and thegenerally axially deploying member comprises a threaded deploymentscrew.

In yet another aspect of the invention, there is provided an implantsystem for use in making an orthopedic repair of a joint, whichcomprises a first implant adapted for receiving a tissue graft thereonand then being disposed in a first bone tunnel location, wherein ends ofthe tissue graft extend through a bone tunnel and out of a proximal endof the tunnel. The first implant comprises a body portion having adistal end and a proximal end, and a first member disposed on the bodyportion which is deployable outwardly to engage adjacent bone foranchoring the implant in place in the tunnel. The first implant furthercomprises a second member disposed on the body portion which isdeployable outwardly to engage tissue material to be fixed within thetunnel, and to move the tissue material outwardly into contact with thetunnel walls. The implant system further comprises a second implantadapted for disposition in a second bone tunnel location, proximal tothe first bone tunnel location. The second implant is adapted to securethe ends of the tissue graft which extend from the first implant againstadjacent bone. The first implant further comprises a third member whichis movable to deploy the first member outwardly. A fourth member isprovided for actuating the third member to move in order to deploy thefirst member.

In still another aspect of the invention, there is disclosed a method ofmaking an orthopedic repair by fixing a soft tissue graft to bone, whichcomprises steps of placing a soft tissue graft on an implant, anddisposing the implant within a bone tunnel at a desired location, suchthat a plurality of ends of the soft tissue graft extend from theimplant in a proximal direction through the bone tunnel. Additionalsteps include deploying a first member on a body of the implantoutwardly so that portions of the first member engage adjacent bone tosecure the implant in place at the desired location, and deploying asecond member on the body of the implant outwardly, so that portions ofthe second member engage portions of the plurality of ends of the softtissue graft and push the soft tissue graft ends into contact withadjacent bone.

The invention, together with additional features and advantages thereof,may best be understood by reference to the following description takenin conjunction with the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an embodiment of a device constructed inaccordance with the principles of the present invention;

FIG. 2A is a top view of the device of FIG. 1 in an undeployedconfiguration;

FIG. 2B is a side view of the device of FIG. 2A;

FIG. 3A is a top view of the device of FIG. 1, wherein the deploymentscrew is starting to deploy the compression pads;

FIG. 3B is a side view of the device of FIG. 3A;

FIG. 4A is a top view of the device of FIG. 1, wherein the compressionpads have been fully deployed;

FIG. 4B is a side view of the device of FIG. 4A;

FIG. 5 is a top view of the device of FIG. 1, wherein the wedge isstarting to deploy the arms;

FIG. 6 is a top view of the device of FIG. 1, wherein the wedge ishalfway engaged;

FIG. 7A is a top view of the device of FIG. 1, wherein the implant hasbeen fully deployed;

FIG. 7B is a side view of the device of FIG. 7A;

FIG. 8 is a view illustrating the implant of FIG. 1, as it is deployedin the femoral tunnel of a patient;

FIG. 9A is a view illustrating tendon compression as effected by theembodiment of FIGS. 1-7;

FIG. 9B is a detail view of a portion of FIG. 9A denoted by a circlelabeled as “9B”;

FIG. 10 is a perspective view, in isolation, of a deployment screw foruse in the embodiment of FIGS. 1-7;

FIG. 11A is a perspective view of a compression pad for use in theembodiment of FIGS. 1-7;

FIG. 11B is a perspective view of a second compression pad;

FIG. 12 is a perspective view of the body of the implant of FIGS. 1-7;

FIGS. 13A and 13B are perspective views of arms for use in theembodiment of FIGS. 1-7;

FIGS. 14A and 14B are perspective views of the wedge for use in theembodiment of FIGS. 1-7;

FIGS. 15A and 15B are perspective views of modified embodiments of theimplant of FIGS. 1-7 with arms flipped to engage with the corticalsurface during a soft tissue repair procedure;

FIGS. 16A and 16B are perspective views of yet another embodiment of theimplant of the invention, wherein the body is used as the wedge;

FIG. 17 is a table summarizing the performance of an implant constructedin accordance with the principles of the present invention, as shown inFIGS. 1-7;

FIG. 18 is an isometric view of a further modified embodiment of theinvention;

FIG. 19 is an exploded view of the embodiment of FIG. 18;

FIG. 20 is a plan view of the embodiment of FIG. 18, in an undeployedconfiguration;

FIG. 21 is a side view of the embodiment of FIG. 20;

FIG. 22 is a plan view of the embodiment of FIG. 20, wherein thedeployment screw is starting to deploy the compression pads;

FIG. 23 is a side view of the embodiment of FIG. 22;

FIG. 24 is a view illustrating the implant of FIGS. 18-23 deployed in afemoral tunnel;

FIG. 25 is a detailed view similar to FIG. 24, showing tendoncompression performed by the deployed inventive device;

FIG. 26 is a perspective view of the deployment screw;

FIG. 27 is a view showing the body of the implant;

FIG. 28 is a view similar to FIG. 27, but showing the implant from adifferent orientation;

FIG. 29 is an isometric view of an arm in accordance with the invention;

FIG. 30 is an isometric view from a different orientation than FIG. 29,showing the arm;

FIG. 31 is a view of the wedge of the invention;

FIG. 32 is a data table;

FIG. 33 is an isometric view of another embodiment of the invention,comprising an undeployed cortical fixation implant;

FIG. 34 is an isometric view of the cortical fixation implant of FIG.33, from a different orientation;

FIGS. 35 and 36 are top and side views, respectively, of the corticalimplant of FIGS. 33 and 34;

FIGS. 37 and 38 are top and side views, respectively, of the corticalimplant of FIGS. 33 and 34, wherein the implant is beginning to bedeployed;

FIGS. 39 and 40 are top and side views, respectively, of the corticalimplant of FIGS. 37 and 38, wherein the implant is in a deployed state;

FIGS. 41 and 42 show a deployment sequence for the cortical fixationimplant;

FIG. 43 is an isometric view of the body of the implant of FIG. 33,showing integrated compression pads;

FIG. 44 is a cross-sectional view of the body of FIG. 43, taken alongthe lines 44-44 of FIG. 45;

FIG. 45 is a side view of the implant of FIG. 43;

FIG. 46 is a perspective view of the wedge of the invention;

FIGS. 47 and 48 are views of the arm of the invention;

FIG. 49 is a perspective view of the compression wedge of the invention;

FIG. 50 is a perspective view of the deployment screw of yet anotherembodiment of the inventive implant; and

FIGS. 51-52 are isometric views of an additional embodiment of acortical implant of the invention, wherein FIG. 51 shows the device inits undeployed configuration and FIG. 52 shows the device in itsdeployed configuration;

FIGS. 53-54 are isometric views of still another embodiment of acortical implant of the invention, wherein FIG. 53 shows the device inits undeployed configuration and FIG. 54 shows the device in itsdeployed configuration; and

FIG. 55 is a view of the femur and tibia of a patient's leg, showing asubstantially completed ACL repair.

DETAILED DESCRIPTION OF THE INVENTION

Referring now more particularly to the drawings, procedures andanchoring devices for repairing soft tissue are illustrated. In FIG. 1,one embodiment of an implant 10, constructed in accordance with theprinciples of the present invention, is shown. The implant 10 comprisesa deployment screw 12, which protrudes through a pair of compressionpads 14 and 16. The implant 10 comprises a body 18, through which thedeployment screw 12 also protrudes. The deployment screw 12, at itsdistal end, is threaded into a wedge 20.

The left compression pad 14 slides into the right compression pad 16,and they attach to one another. Two pins 22 attach a pair of arms 24 tothe body 18. There is a track 26 on each side of the wedge 20, best seenin FIG. 14A. Each wedge track 26 attaches to a track post 28 (FIG. 13B)on a corresponding one of the arms 24. The wedge tracks 26 function toprevent the wedge from rotating during deployment of the implant.

The compression pads 14, 16 slide into a pair of body tracks 30 (FIG.12) in the body 18, which allow the pads 14, 16 to expand when thedeployment screw 12 is rotated clockwise, as shown in FIGS. 2-4. Thebody tracks 30 also prevent the pads 14, 16 from rotating.

In FIG. 10, the deployment screw 12 is shown in detail. This screw 12comprises a quad lead section 32, with four separate thread starts. Thismeans that, for every single turn on the screw, the linear distance ittravels is four times what a single lead screw would be. This featureenables the user to turn the screw fewer times than would be requiredwith a single start thread, approximating the same number of turns thatthe user would need during the implantation of an interference screwsuch as the above described Smith & Nephew RCI screw. Often, duringimplantation, an interference screw requires a notch to be placed at theedge of the femoral tunnel aperture to allow the screw to start engaginginto the bone. Advantageously, the need for this step is eliminated whendeploying the implant of the present invention, resulting in asubstantially easier implementation procedure.

Accordingly, the present invention is easy to deploy as an interferencescrew, and requires fewer steps than in prior art approaches. Thedeployment screw 12 also provides a rigid backbone to support theimplant. A screw head or compression pad deployer 34 deploys thecompression pads 14, 16 as the screw 12 moves axially into the implant.Another feature of the screw 12 is a load transfer disk 36 thattransfers some of the axial load from a junction between the screw head34 and the body 18 to a junction between the load transfer disk 36 andthe body 18. This load transferring feature allows for thinner sidewalls or struts 38 on the body 18 due to a decreased load on struts 38(FIG. 12), which, in turn, allows a larger tendon to fit between thedeployment screw 12 and the body 18.

With reference now particularly to FIGS. 11A and 11B, the compressionpads 14 and 16 are shown in greater detail. The left and rightcompression pads 14, 16, respectively, compress the tendons against thefemoral tunnel wall to promote tendon-to-bone healing at the aperture ofthe tunnel. Unlike current approaches for more intimate tendon-to-bonecontact that only reduce the space between the tendon and the tunnelwall, the present invention actively compresses the tendons against thebone tunnel. Compression pad tracks 40 engage the body tracks 30 andinterlock them to the body 18. This joint also provides torsionalresistance while moving the implant into place, and during initialdeployment until the arms 24 start to engage with the bone. There areengagement slots 42 in each compression pad 14, 16, as shown, thatengage with a deployment device that keep the implant 10 from rotatinguntil the arms 24 engage the bone. The two compression pads 14, 16 snaptogether using compression pad snaps 44 to prevent premature deploymentof the pads.

Now referring to FIG. 12, the body 18 functions to trap the tendons oneither side of the deployment screw 12. The compression pads 14, 16engage the body tracks 30 and provide torsional strength to the bodywhile inserting the implant into the femoral tunnel, thus allowing thecompression pads 14, 16 to expand parallel to one another. The struts 38also provide structural support for the deployment screw 12, wedge 20,and arms 24 to deploy against.

The arms 24 have a few key design features, as best shown in FIGS. 13Aand 13B. Fins 46 on the top of each arm provide torsional strength forthe wedge-to-arm junction. The fins 46 also allow easier insertion intothe femoral tunnel when inserting into a femoral tunnel that is drilledoff-axis from the tibial tunnel. The portion of the arm 24 that engageswith the bone has a tapered edge 48 which allows for ease of bonedisplacement during deployment. A support rib 50 disposed along thelength of the arm 24 is also tapered for ease of bone displacement, andprovides structural support during axial loading. Torsion pins 52 engagewith a torsion hole 54 to provide additional torsional strength whilethe implant is being implanted into the femoral tunnel.

FIGS. 14A and 14B show, in greater detail, particular constructionalfeatures of the wedge 20. The wedge 20 is threaded with a female quadlead thread 56 that matches the male quad lead thread 32 of thedeployment screw 12. The track posts 28 engage with the wedge tracks 26to provide torsional strength through deployment. A tapered nose 58 onthe wedge 20 allows easier off-axis insertion into the femoral tunnel.

Referring now to FIGS. 2-9, a preferred method of using the disclosedinventive implant will now be discussed. In FIGS. 2A and 2B, the implant10 of FIG. 1 is shown in its undeployed orientation. A preferredprocedure for deploying the implant is generally similar in manyrespects to the procedure disclosed in U.S. Patent ApplicationPublication No. 2006/0155287, herein already expressly incorporated byreference.

Thus, to accomplish tendon fixation using the exemplary methods anddevices described herein, standard surgical preparation of the siteand/or arthroscopic portals for access to the procedural region areperformed. The joint is dilated with arthroscopic fluid if the procedureis to be performed arthroscopically. With open procedures, the devicemay easily be manipulated and deployed with a single hand. Forarthroscopic procedures, the deployment device is introduced through astandard 5, 6, or 8 mm cannula placed into the joint. A range ofpreferred cannula sizes would be 2-11 mm.

The procedures described herein are specifically adapted to repair ofthe ACL in a patient's knee. However, it should be kept in mind that theimplants described herein may be used in numerous other soft tissuerepair applications, using surgical procedures which are adapted tothose applications.

FIGS. 8 and 9A illustrate, from two different orientations, a hamstringACL reconstruction, wherein the implant 10 is utilized to secure the ACLgraft proximal to the femur 60 and distal to the tibia 62 of a patient.To deploy the implant 10, a bone tunnel 64 is drilled completely throughthe tibia 62 and partially through the femur 60. An actuator (not shown)is employed to insert the implant 10 distally through a tibial inletaperture 66 and through the tibial tunnel 64, so that the implant isfinally disposed in a portion of the tunnel 64 which is within the femur60, distal to a femoral aperture 68, as shown in FIGS. 8 and 9A.

Now with respect to FIGS. 3 and 3A, once the implant 10 is in placewithin the femoral tunnel 64, as shown in FIG. 8, the deployment screw12 is actuated (rotated) in order to advance the screw 12 axiallydistally into the implant body 18, and thus begin to deploy or expandthe compression pads 14 and 16 outwardly. FIGS. 4 and 4A depict the nextstep, wherein advancement of the deployment screw 12 has caused thecompression pads 14, 16 to fully deploy. As noted above, the screw heador compression pad deployer 34 acts to deploy the compression pads 14,16 as it moves distally into the implant 10, as shown.

As the deployment screw 12 continues to move distally through theimplant 10, the distal end of the screw 12, comprising the male quadlead section 32 (FIG. 10), engages the female quad lead thread 56 of thewedge 20 (FIG. 14B). Continued axial distal movement of the screw 12causes the threaded sections 32 and 56 to cooperate to move the wedge 20axially in a proximal direction, as shown in FIG. 5. This proximalmovement of the wedge 20 causes the arms 24 to begin to deployoutwardly. In FIG. 6, the wedge 20 is shown in a position where it isabout halfway engaged within the separating arms 24.

In FIGS. 7A and 7B, the wedge 20 is fully proximally engaged with thebody 12 of the implant 10, such that the arms 24 are, consequently,fully deployed. In FIG. 8, the implant 10 is shown in this fullydeployed condition.

FIGS. 9A and 9B illustrate tendon compression as effected by thedeployed implant 10. In these figures, tendons 70 are compressed bydeployed compression pads 14, 16 against the femoral tunnel wall inorder to promote tendon-to-bone healing at the aperture of the tunnel.Advantageously, the inventive approach actively compresses the tendonsagainst the bone tunnel.

Alternative implant designs are shown in FIGS. 15 and 16. In particular,FIGS. 15A and 15B illustrate an alternative embodiment (with likeelements being labeled with like reference numerals to those used inconnection with the embodiment of FIG. 1) wherein the arms 24 areflipped to the other side of the body 18. The modified arms 24 aredesigned to permit the tendons (not shown) to pass by them and engagewith the cortical bone. The arm-to-body joint is a pin-less design witha track way in the body that secures the arm 24 in place.

FIGS. 16A and 16B illustrate yet another modified embodiment wherein,once again, like elements are labeled with like reference numerals asthose used in connection with the earlier embodiments. In thisembodiment, the implant 10 uses the body 18 as a wedge.

Testing has been done by the inventors to verify the functionality ofthe disclosed invention of FIGS. 1-7. As shown in FIG. 17, the inventorsfound that pull-out forces for the implant 10 were significantly higherthan those of a predicate device, the RCI interference screw availablefrom Smith & Nephew.

In FIGS. 18-21 there is shown another implant embodiment 110, whereinlike elements are identified with like reference numerals as for theembodiment of FIGS. 1-14, preceded by the numeral 1. As shown, thedeployment screw 112 protrudes through the compression pads 114 and 116,which are each integrated into the body 118. The deployment screw 112 isthreaded at its distal end into the wedge 120. Two pins 122 attach apair of arms 124 to the body 118, as shown.

As noted above, in this embodiment the compression pads 114, 116 areintegrated into the body 118. This feature permits the use of a shorterimplant than is the case for the implant of FIG. 1. A track 126 in thewedge 120 attaches to track posts 128 on the arms 124 (FIG. 29), whichkeep the wedge 120 from rotating during deployment. The compression padsexpand as the implant is deployed. In particular, the screw 112 expandsthe pads 114, 116 outwardly by sliding on a compression taper 72 (FIG.27), as shown in FIGS. 20-23. Moreover, as the deployment screw 112rotates, the wedge 120 expands the arms 124 as also shown in FIGS.20-23. Once the screw 112 is fully seated, the expanded arms 124 fullyengage with adjacent cancellous bone 74, thus locking the anchor inplace, as shown in FIG. 24.

The deployment screw 112 (FIG. 26) has a male quad lead section 132 withfour separate thread starts, as in the prior disclosed embodiment. Thismeans that for every one rotation of the screw, the linear distance ittravels is four times that which a single lead screw would travel. Thisenables the user to turn the screw fewer times than would be requiredwith a single start thread, approximating the same number of turns thatthe user would need during the implantation of an interference screwsuch as the RCI screw available from Smith & Newphew. Oftentimes, duringimplantation, an interference screw such as the RCI screw requires anotch to be placed at the edge of the femoral tunnel aperture to permitthe screw to start engaging the bone. However, the present inventionavoids the need for such a step, resulting in an easier implantationprocedure. The invention is easy to deploy as an interference screw, andrequires fewer steps. The deployment screw 112 also provides a rigidbackbone to support the implant. A reverse threaded hex 75 is preferablyprovided to drive the screw.

The screw head or compression pad deployer 134 deploys the compressionpads 114, 116 as the screw 112 advances axially into the implant.Another feature of the screw is the provision of a load transfer disk136 that transfers some of the axial load from the screw head 134 tobody junction to the disk to body junction. This allows for thinner sidewalls or struts 138 on the body 118 due to the decreased load on thestruts, which in turn allows a larger tendon to fit between thedeployment screw 112 and the body 118.

As shown in FIG. 25, the compression pads 114, 116 compress the tendons170 against the femoral tunnel wall to promote tendon-to-bone healing atthe aperture of the tunnel. Unlike prior art approaches for moreintimate tendon-to-bone contact that only reduce the space between thetendon and the tunnel wall, the present invention actively compressesthe tendons against the bone tunnel. The compression pads 114, 116 inthis embodiment are integral with the body 118.

The body 118 functions to trap the tendons 170 on either side of thedeployment screw 112. The struts 138 are split, as shown at referencenumeral 76 (FIG. 28), to allow the integrated compression pads 114, 116to expand and compress the tendon against the bone tunnel. They alsoprovide structural support for the deployment screw 112, wedge 120, andarms 124 to deploy against.

The arms 124 include a few key design features, as particularly shown inFIGS. 29 and 30. Fins 146 on the top provide torsional strength for thewedge 120 to arm 124 junction. They also allow easier insertion into thefemoral tunnel when inserting into a femoral tunnel that is drilledoff-axis from the tibial tunnel. The portion of the arm 24 that engageswith the bone has a tapered edge 148 which allows for ease of bonedisplacement during deployment. The support rib 150 along the length ofthe arm 124 is also tapered for ease of bone displacement and providesstructural support during axial loading. The torsion pins 152 engagewith a torsion hole 154 to provide additional torsional strength whileinserting into the femoral tunnel.

As in the prior embodiment, the wedge 120 is threaded with a female quadlead thread 156 that matches the complementary threads 132 on thedeployment screw 112. The track posts 128 on the arms 124 engage withthe wedge track 126 to provide torsional strength through deployment. Atapered nose 158 allows easier off-axis insertion into the femoraltunnel.

FIG. 32 is a table similar to that of FIG. 17, presenting data generatedby the inventors which indicates that pull-out forces for the implant110 were significantly higher than those of a predicate device, the RCIinterference screw available from Smith & Nephew.

Still another embodiment of the inventive implant is illustrated inFIGS. 33-54, wherein like elements to those of the prior embodiments areidentified by like reference numerals, preceded by the numeral 2. Thisembodiment 210 utilizes the cortical bone for fixation in combinationwith tendon-to-bone compression. In this version of the invention, thedeployment screw 212 is offset to one side of the implant 210, for thepurpose of permitting easier passing of tendon through the orifice. Thisimplant deploys in two steps. The deployment screw 212 is rotatedclockwise as an arm 78 and wedge 220 slide together across tapered faces80 (FIG. 46) and 82 (FIG. 48) until they lock together with theirrespective cortical locks 84, 86. The wedge 220 and the arm 78 lock intoplace by filling a majority of the cross section of the femoral tunnel.Thus, the implant is free to move in the femoral tunnel, allowingtactile feedback to ensure engagement of a cortical tab 88 with thecortex.

The screw is then rotated so that it is advanced the remainder of theway, and the compression wedge 90 engages with the compression pads,thereby pressing the tendon against the bone tunnel wall. A track 92, 94in the compression pads 214, 216 and compression wedge 90 prevents thecompression wedge from engaging unevenly. A progression of deployment ofthe implant 210 is illustrated in FIGS. 35-42. FIGS. 43-50 illustratevarious components of the embodiment. In the undeployed state, the armis engaged with the wedge with the arm's track posts 228 engaging with aT-bar 96 of the wedge 220. This prevents the arm 78 from moving duringinsertion. Also, to prevent the wedge 220 from rotating duringdeployment, the track post 228 is inserted into a torsion slot 100.

Modified cortical fixation implant designs are illustrated in FIGS.51-54. FIGS. 51 and 52 illustrate a modified wedge and only one armwhich allows engagement with the cortical bone. FIGS. 53 and 54illustrate the same embodiments as in FIGS. 51 and 52, wherein the screwis to one side of the implant.

FIG. 55 has been incorporated into this application to illustrate asubstantially completed ACL repair procedure. FIGS. 8 and 9, as well asFIGS. 24 and 25 and FIGS. 41 and 42, illustrate the installation of thefemoral anchor of the present invention, in various embodiments.However, as one skilled in the art would understand, to complete therepair procedure further steps are necessary. Once the femoral anchorhas been deployed and installed, as previously described, the anchoredtendons 70 extend proximally from the femoral tunnel through the tibialtunnel and out through tibial aperture 66. To complete the procedure, atibial anchor 102 is preferably installed, to anchor the tendon bundlesin place, as shown in FIG. 55. Once this anchor is in place, theproximal ends of the tendon bundles are trimmed to complete theprocedure. This portion of the ACL reconstruction procedure is fullyexplained in co-pending U.S. application Ser. No. 11/725,981, which hasalready been fully and expressly incorporated by reference herein. Anysuitable tibial anchor 102 may be used in conjunction with femoralanchors of the type disclosed in this application, but the tibialanchors shown and described in the '981 patent application are presentlypreferred.

Accordingly, although exemplary embodiments of the invention has beenshown and described, it is to be understood that all the terms usedherein are descriptive rather than limiting, and that many changes,modifications, and substitutions may be made by one having ordinaryskill in the art without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A material fixation system, comprising: animplant comprising a body having a distal end and a proximal end, whichis placeable in a tunnel disposed in a portion of bone, wherein thetunnel is defined by walls comprised of bone; a first member on saidbody which is deployable outwardly to engage adjacent bone for anchoringsaid implant in place in the tunnel, the first member having engagingsurfaces which extend outwardly relative to remaining portions of thefirst member; and a second member on said body and spaced axially fromsaid first member, which is deployable outwardly to engage tissuematerial to be fixed within said tunnel, and to move the tissue materialoutwardly into contact with the tunnel walls, the second member havingengaging surfaces which are substantially broader and flatter than theengaging surfaces of the first member, for more effectively compressingthe tissue material against the tunnel walls without penetrating thetissue; a third member which is movable to deploy said first memberoutwardly; and a fourth member having an enlarged portion which ismovable to contact inner sides of the engaging surfaces of the secondmember to deploy them outwardly, so that outer sides of the engagingsurfaces of the second member engage the tissue material to move itoutwardly into contact with the tunnel walls.
 2. The material fixationsystem as recited in claim 1, wherein said third member is movableaxially to deploy said first member outwardly.
 3. The material fixationsystem as recited in claim 2, wherein said fourth member actuates saidthird member to move in order to deploy said first member.
 4. Thematerial fixation system as recited in claim 3, wherein said fourthmember enlarged portion moves axially to deploy said second memberoutwardly.
 5. The material fixation system as recited in claim 3,wherein said first member comprises an arm which is pivotally attachedto said body.
 6. The material fixation system as recited in claim 5,wherein said third member comprises a wedge which is movable generallyaxially to deploy said arm.
 7. The material fixation system as recitedin claim 6, wherein said fourth member comprises a deployment screwhaving a distal end and a proximal end, said deployment screw beingadapted to extend axially through said body, the distal end of saiddeployment screw having a threaded portion which is engageable with acomplementary threaded portion on said wedge, wherein rotation of saiddeployment screw causes relative movement of said deployment screw andsaid wedge.
 8. The material fixation system as recited in claim 7,wherein said wedge moves proximally to deploy said arm.
 9. The materialfixation system as recited in claim 1, wherein the engaging surfaces ofsaid second member comprise compression pads.
 10. The material fixationsystem as recited in claim 4, wherein said fourth member enlargedportion comprises a head of said deployment screw, disposed on theproximal end thereof.
 11. An implant system for use in making anorthopedic repair of a joint, said implant system comprising: a firstimplant adapted for receiving a tissue graft thereon and then beingdisposed in a first bone tunnel location, wherein ends of the tissuegraft extend through a bone tunnel and out of a proximal end of thetunnel, said first implant comprising: a body portion having a distalend and a proximal end; a first member disposed on said body portionwhich is deployable outwardly to engage adjacent bone for anchoring saidimplant in place in the tunnel; and a second member disposed on saidbody portion which is deployable outwardly to engage tissue material tobe fixed within said tunnel, and to move the tissue material outwardlyinto contact with the tunnel walls; a third member which is movable todeploy said first member outwardly; and a fourth member having anenlarged portion which is movable to contact inner sides of the secondmember to deploy them outwardly, so that outer sides of the engagingsurfaces of the second member engage the tissue material to move itoutwardly into contact with the tunnel walls; and a second implantadapted for disposition in a second bone tunnel location, proximal tosaid first bone tunnel location, said second implant being adapted tosecure the ends of the tissue graft which extend from the first implantagainst adjacent bone.
 12. The implant system as recited in claim 11,wherein said first implant further comprises a third member which ismovable to deploy said first member outwardly.
 13. The implant system asrecited in claim 12, and further comprising a fourth member foractuating said third member to move in order to deploy said firstmember.
 14. A material fixation system, comprising an implant which isplaceable in a space defined by bone, said implant comprising: a bodyhaving a distal end and a proximal end; a first member on said bodywhich is expandable outwardly to engage portions of the bone, the firstmember having engaging surfaces which extend outwardly relative toremaining portions of the first member; a second member on said bodywhich is distal to said first member; said second member being movablein a proximal direction relative to said first member, wherein proximalmovement of said second member actuates said first member to expandoutwardly to engage the bone, thereby securing the implant in placewithin the space; a third member on said body and spaced axially fromsaid first member, which is deployable outwardly to engage tissuematerial to be fixed within said tunnel, and to move the tissue materialoutwardly into contact with the tunnel walls, the third member havingengaging surfaces which are substantially broader and flatter than theengaging surfaces of the first member, for more effectively compressingthe tissue material against the bone without penetrating the tissue; anda fourth member having an enlarged portion which is movable to contactinner sides of the engaging surfaces of the third member to deploy themoutwardly, so that outer sides of the engaging surfaces of the thirdmember engage the tissue material to move it outwardly to compress thetissue material against the bone.
 15. The material fixation system asrecited in claim 14, wherein said second member is actuated byapplication of tension thereon.
 16. The material fixation system asrecited in claim 14, wherein said first member comprises an arm which ispivotable outwardly, said arm having a portion which is adapted toengage bone to anchor the body to the bone.
 17. The material fixationsystem as recited in claim 16, wherein said first member comprises aplurality of said arms.
 18. The material fixation system as recited inclaim 14, wherein said second member comprises part of a deploymentdevice which is movable in a generally axial direction to deploy bothsaid first and third members.
 19. The material fixation system asrecited in claim 14, wherein the engaging surfaces of said third membercomprise compression pads.